title: Development of long-term specific cellular immunity after acute Blastomyces dermatitidis infection: assessments following a large point-source outbreak in Wisconsin.
abstract: Ninety-five persons exposed to a point-source of Blastomyces dermatitidis in Wisconsin in 1984 were evaluated 3 months after exposure for the development of specific cellular immunity, and the 48 infected persons were again evaluated 7 and 21 months after exposure. The immune response was assessed by an assay of [3H]thymidine uptake by lymphocytes proliferating in response to stimulation with Blastomyces alkali- and water-soluble antigen (B-ASWS) or blastomycin and by skin testing with blastomycin. At 3 months, 36 (84%) of 43 patients demonstrated a proliferative response to B-ASWS (mean value of experimental [E]-control [C] counts, 16,852 +/- 2664, and of E/C, 42.2 +/- 5.3). None of the patients demonstrated a proliferative response to blastomycin, and only 19 (41%) of 45 patients tested had a positive blastomycin skin test. By 21 months, 47 (98%) of the 48 patients demonstrated a proliferative response to B-ASWS on at least one testing date. Of those initially positive, 82% had a persistently positive proliferative response at 21 months; mean E-C and E/C values were comparable to those seen at 3 months. None of the 47 uninfected persons demonstrated a proliferative response to B-ASWS: 7 with positive histoplasmin skin tests had a mean E-C value of 1094 +/- 432, and the 40 others, a mean value of 1139 +/- 212. A proliferative response to B-ASWS in exposed individuals is a reliable marker of specific cellular immunity in blastomycosis and the response persists in most patients for up to at least 2 years.
authors.affiliation: Department of Pediatrics, University of Wisconsin Clinical Sciences Center.
authors.forename: B S
authors.initials: BS
authors.lastname: Klein
authors.forename: R W
authors.initials: RW
authors.lastname: Bradsher
authors.forename: J M
authors.initials: JM
authors.lastname: Vergeront
authors.forename: J P
authors.initials: JP
authors.lastname: Davis
mesh_terms: D000208:Acute Disease; D000946:Antigens, Fungal / Q000276:immunology; D000968:Antimycin A / Q000031:analogs & derivatives / Q000276:immunology; D001759:Blastomycosis / Q000453:epidemiology / Q000276:immunology*; D002648:Child; D004196:Disease Outbreaks; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007111:Immunity, Cellular; D008213:Lymphocyte Activation; D008297:Male; D012882:Skin Tests; D014922:Wisconsin
chemical_list: D000946:Antigens, Fungal; D000968:Antimycin A; C004510:blastmycin